Edwards PRG20K, Instruction Manual, Page: 14 / 24

D0300020001EN - Installation
Page 8
the gauge head and the protective earth conductor screw on the rear of the PGC201/PGC202
controller.
Ensure that the correct filament material is selected on the PGC201/PGC202 controller. Refer
to the operating instructions for the PGC201/PGC202 controller.
Ensure the correct filament material is selected (tungsten or platinum) when operating the
gauge head in connection with an operating unit PGC201 and PGC202 (see Operating
Instructions PGC201 and PGC202).
The connecting plug can be safely attached to the gauge via the securing clip. To do so, push
the clip over the connecting pug and let them snap in the provided holes which are in the
shell.
Adjustment of the gauge head
Adjustment is performed as follows:

Remove the caps covering the potentiometers on the gauge head.

Vent vacuum system and set 100% potentiometer ( Figure 2 item 1) so that the
controller indicates full scale (atmospheric pressure).

Pump down vacuum system to a pressure below 5 x 10
-4
mbar and set "0"
potentiometer ( Figure 2 item 2) so that the controller indicates 0.

Vent vacuum system and recheck the 100% adjustment. Correct deviation, if any, by
means of potentiometer.

If a correction of the 100% adjustment was necessary the zero adjustment must be
repeated in any case.

After having completed the adjustment fit the caps to cover the potentiometers.
Figure 2 Gauge head PRG20K - NW16 Al / PRG20K - DN16CF SS / PRG20KCR - NW16 SS
Adjustment of the gauge head in connection with operating units
PGC201 and PGC202
Refer to the operating instructions supplied with the PGC201 or PGC202.
Note:
The ground wire may only be connected if potential equalization between the flange of the
vacuum apparatus and the operating unit is ensured. If necessary install the gauge head so
that it is electrically isolated from the vacuum apparatus.
1 100% potentiometer
2 0% potentiometer